Improvement in converting cast-iron into malleable iron



ALrxANnEn IIAMAn, or PHILADELPHIA, PENNSYLVANIA, AND eEoneE II. sELLEEs, or WILMINGTON, DELAWARE.

IMPROVEMENT IN CONVER'TING CAST-IRON INTO MALLEABLE IRON.

Spotdliention foriniixg part oi' Letters Patent No. 36,537, dated February 52, 1869.

v Tcall whom it may concern:

vPennsylvania, but now residing at Wilmington, in the State of Delaware. have invented certain .new and Improved Methods of Gonverting Cast Iron into Malleablc Iron, of which the following is a full, clear, and exact description.

The object of the first part of our invention is to form good malleable iron by removing the impurities from the metal while in a molten state to which end cmrimprovemeut consists ina novel method of applying a current of electricity to a current of metal;` whereby the foreign matters are etfectually eliminated, as their affinity is for the negative pole of the battery, while that of the iron is equally strong for the opposite or positive pole.

Our invention further consists in a novel methodof applying a current of electricity toV a current of molten metal, to eliminate its impnrities, and simultaneously subjecting the metal to a strong upward current of hot compressed air and hydrogen, or oxygen, or both combined, which gases combine with the freed carbon of the metal and consume it, While the oxygen at the same time oxidizes the silicates, and (together with the heat generated by the `combustion of the carbon) burns off or vaporizes the sulphur, phosphorus, or arsenic eliminated from the iron by the electric current.

Our improvement further consists in a novel method of forming a bed or hearth for the boty tom of the furnace'in which 'the cast-iron is melted, offene volume of nitrate ot' soda, ve volumes of charcoal, and enough lime slaked in water to form a stiff paste of the entire mass, whereby the iron is purified, as hereinafter explained.

rJhe next part of our invention relates to an improved apparatus for carrying out the objects of our invention; and our improvement under this head consists in a novel method of combining a furnace to melt the iron, an insulated ladle to receive the molten metal, a stack through which the melted metal runs, and an electric battery or circuit, so arranged as to transmit its current through the metal during its descent.

Our invention further consists .in a novel method of combining with the stack an adjustable scattering-cone, carrying`an insulated Wire. f

Our invention further consists in-a novel method `of combining with the. stack an anunlar blowing-chamber, provided with proper tuyeres to admit the blast.

The accompanying drawing/:which exemplifies one practical Inode of ,carrying outour invention, is a view, partly ,in elevation and partly in section, of sormuch of our improved converting apparatus as is necessary to illustrate our invention. y The iron to be converted is first melted in a cupola or air -furna-ce, A. Before charging this furnace its bottom is covered with a. bed or hearth composed of.y the following ingredients, mingled iny the proportions given, vizi" `Nitrate of soda, one volume; pulverized charcoal, live volumes; slaked lime, mixed with water, enough to form a thin paste. These ingredients are the furnace is to be charged with coal and pig iron, in the usual way.. As the iron melt-s,

'the nit-rate of soda evolves oxygen gas, which bubbles up through the molten metal, and puriies the iron by depriving it of its phosphorus and sulphur. The iron is also, by this process, depri-ved of a part of its carbon, but this loss. is repaired by the carbon evolved from the charcoal. The. lime acts as a flux, to some extent. We have found this much of our process beneficial in purifying iron without more. 4 y

To carry out the next part of our invention, the molten metal is run, at suitable periods, through a trough, a, into a ladle, B, electrically insulated in any proper well-known way, and connected with the magnetic pole of a strong battery by a wire, n.

We prefer to place in the ladle B p ulverized hematite,'or other pulverized oxides of iron, in the proportion of about one-twentieth of the volume of the iron that the Vladle is to receive. y

(A spout, b, conducts the melted iron from the ladlev into a stack, C, into which it falls,

to be mixed into a stiff mortar, and spread over the hearth. When dry, v

a eases and is scattered into spray by acoue,-D, secured on suitable bars c some distance below the top of the stack, and suitably protected .from the heat by re-clay or equivalent means.

.e Itzwill be seenY that Yin our Yprocess YtheV cur-Y rent of fallingmetal itself forms the connec-V tion between 'the two poles of the battery.

The stack C, in this instance, is formed of an outer casing, E, of iron, lwith I an internal lining,'e,` of re clay or brick, so arranged as to leave an annular space, e2, between them.

`This space serves as a blowing-chamber,

through which a blast of air, compressed un. der high pressure, (either hot or cold, hydrogen or oxygen,),is forced int.) thestack bynumerous openings, f, at different'elevatons, by which means a continuous supply of fresh gases is secured, as hereinafter explained.

The hydrogen or oxygen of the blast encounters the falling metal just as it is chemi' cally separated from its impurities by the electric current, and immediately unites with the carbon of the metal, forming carbureted hydrogen or oxygen, as the case may be, which, by

its combustion, destroys or eliminates the other impurities ofthe iron. A small furnace, G, is placed near the bottom of the stack to heat it, and prevent chilling the iron. `The fuel is placed on' a grate, h. Mingled jets of steam 'and air are introduced intothe furnace below the hearth through a pipe, I, from any proper blowing apparatus. The oxygen of the steam is consumed by the re, and the remaining product (carbureted hydrogen) escapes up the stack through the opening K, andaids in puri- Vtying the iron. The blast is conducted to the furnace and stack through a pipe, L, in the usual'way Thel purified iron is `run directly from the stack into molds to` in `ots..

We nd by experiment that/we produce malleable iron of excellent quality by our process at a moderate cost.

What we claim as our invention, and desire vto secure by Letters Patient, is--e l. .The method herein described of convert ing castiron into malleable iron, by exposing the current of melted metal to a current of electricity.

' 2. The 1nethfthereinY described ifcoliyert-r ing east-iron into rmalleable iron, by the ap plicatiou of a current of electricity to the current of melted metal, in combination withthe application to the metal, While passing through the stack, of a strong blast of hydrogen or oxygen, or both combined.-

3. A hearth for a melting-furnace composed of nitrate of soda, charcoal, and lime, substantially as set forth.J

4. The combination, substantially as set forth,of a furnace to melt the iron, an insulated ladle to receive the melted metal from the furnace, and a stack through which the metal falls in a stream or shower, with an electric current acting on the falling metal.

5. The combination, substantially as set l'orthwith the stack, of the adjustable scat` tering-cone and its electric wire, whereby we are enabled to regulate the length of exposure ofthe metal to the electric current.

6. The combinatiom substantially as set forth, with the stack, of the annular blowingchamber and the blast-orifices, whereby a continued supply of fresh gases is kept up -to the falling shower or stream of melted metal.

In testimony whereof We have hereunto subscribed our names.

A. HAMAR. 4 GEORGE ll. SELLERS. Witnesses:

WM. B. DAYTON, HENRY BALDWIN, Jr. 

